ASTM C738-94(2020)
(Test Method)Standard Test Method for Lead and Cadmium Extracted from Glazed Ceramic Surfaces
Standard Test Method for Lead and Cadmium Extracted from Glazed Ceramic Surfaces
ABSTRACT
This test method details the standard and precise procedures for the determination of lead and cadmium extracted by acetic acid from glazed ceramic surfaces. The apparatus needed for this procedure include an atomic absorption spectrometer, lead and cadmium lamps, and glassware of chemical resistant borosilicate glass. The water, detergent wash, and reagents such as acetic acid, lead nitrate solution, hydrochloric acid, and cadmium solution should conform to chemical purity specified. Measurement procedures, precision, and bias are discussed thoroughly.
SCOPE
1.1 This test method covers the precise determination of lead and cadmium extracted by acetic acid from glazed ceramic surfaces. The procedure of extraction may be expected to accelerate the release of lead from the glaze and to serve, therefore, as a severe test that is unlikely to be matched under the actual conditions of usage of such ceramic ware. This test method is specific for lead and cadmium.
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
- Status
- Published
- Publication Date
- 31-Oct-2020
- Technical Committee
- C21 - Ceramic Whitewares and Related Products
- Drafting Committee
- C21.03 - Methods for Whitewares and Environmental Concerns
Overview
ASTM C738-94(2020) - Standard Test Method for Lead and Cadmium Extracted from Glazed Ceramic Surfaces provides a precise and standardized process to quantitatively determine the amount of lead and cadmium that can be leached from the surfaces of glazed ceramics using acetic acid extraction. This method employs atomic absorption spectrometry for detection and is widely recognized as a severe, accelerated test, exceeding typical conditions encountered in actual product usage. Developed under ASTM Committee C21 on Ceramic Whitewares and Related Products, this standard aligns with internationally recognized principles and supports the World Trade Organization Technical Barriers to Trade (TBT) Committee guidance.
Key Topics
- Lead and Cadmium Extraction: The test measures the amount of lead and cadmium released by glazed ceramic surfaces when subjected to a 4% acetic acid solution for 24 hours at room temperature (20–24°C).
- Precision and Bias: Procedures ensure high repeatability and include guidance for laboratory precision and interlaboratory reproducibility, supporting statistically sound safety assessments.
- Chemical Purity and Apparatus: All reagents and glassware, including acetic acid, hydrochloric acid, and standard solutions of lead nitrate and cadmium sulfate, must meet specified chemical purity standards. Chemically resistant borosilicate glassware and a properly calibrated atomic absorption spectrometer are essential.
- Safety and Regulatory Compliance: The standard underscores the importance of implementing appropriate safety, health, and environmental practices, and evaluating regulatory requirements relevant to hazardous substances in ceramics.
- Reporting and Interpretation: Results are reported in parts per million (ppm) for each unit tested, supporting compliance with health and safety regulations.
Applications
The ASTM C738-94(2020) test method is widely applied in the following areas:
- Quality Assurance for Glazed Ceramics: Helps manufacturers and quality control laboratories assess the safety of ceramic products such as tableware, cookware, and decorative items.
- Regulatory Compliance: Supports conformance with national and international regulations governing heavy metal content, especially where lead and cadmium release limits are specified.
- Consumer Protection: Reduces health risks associated with exposure to toxic heavy metals by providing a reliable gauge for product safety before market release.
- Research and Development: Assists researchers in evaluating new ceramic glaze formulations or production processes, promoting safer materials innovation.
- Inter-laboratory Comparison: Enables benchmark testing and standardization across different facilities to ensure uniform testing procedures and comparable results.
Related Standards
For broader context and complementary guidance on heavy metal analysis and ceramic product safety, consider these related standards:
- ASTM C927 - Practice for Selection and Use of Materials for the Production of Porcelain Enamels on Steel
- ISO 7086-1 - Glass Hollowware-Release of Lead and Cadmium-Part 1
- ISO 6486-2 - Ceramic Ware, Glass Ceramic Ware and Glass Dinnerware in Contact with Food-Release of Lead and Cadmium-Part 2: Permissible Limits
- AOAC Official Methods 973.32 - Comparable method for lead and cadmium extraction from ceramics
- ASTM C282 - Practice for Sampling of Ceramic Whitewares
Practical Value
Adhering to ASTM C738-94(2020) ensures reliable testing of lead and cadmium release from glazed ceramics, enhancing product safety and customer confidence while helping manufacturers meet regulatory and market demands. This standard plays a crucial role in supporting public health objectives by minimizing exposure to hazardous substances from frequently used ceramic goods.
Keywords: ASTM C738, lead extraction, cadmium extraction, glazed ceramic surfaces, acetic acid leaching, atomic absorption spectrometry, ceramic safety, regulatory compliance, heavy metal testing, consumer product safety.
Frequently Asked Questions
ASTM C738-94(2020) is a standard published by ASTM International. Its full title is "Standard Test Method for Lead and Cadmium Extracted from Glazed Ceramic Surfaces". This standard covers: ABSTRACT This test method details the standard and precise procedures for the determination of lead and cadmium extracted by acetic acid from glazed ceramic surfaces. The apparatus needed for this procedure include an atomic absorption spectrometer, lead and cadmium lamps, and glassware of chemical resistant borosilicate glass. The water, detergent wash, and reagents such as acetic acid, lead nitrate solution, hydrochloric acid, and cadmium solution should conform to chemical purity specified. Measurement procedures, precision, and bias are discussed thoroughly. SCOPE 1.1 This test method covers the precise determination of lead and cadmium extracted by acetic acid from glazed ceramic surfaces. The procedure of extraction may be expected to accelerate the release of lead from the glaze and to serve, therefore, as a severe test that is unlikely to be matched under the actual conditions of usage of such ceramic ware. This test method is specific for lead and cadmium. 1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
ABSTRACT This test method details the standard and precise procedures for the determination of lead and cadmium extracted by acetic acid from glazed ceramic surfaces. The apparatus needed for this procedure include an atomic absorption spectrometer, lead and cadmium lamps, and glassware of chemical resistant borosilicate glass. The water, detergent wash, and reagents such as acetic acid, lead nitrate solution, hydrochloric acid, and cadmium solution should conform to chemical purity specified. Measurement procedures, precision, and bias are discussed thoroughly. SCOPE 1.1 This test method covers the precise determination of lead and cadmium extracted by acetic acid from glazed ceramic surfaces. The procedure of extraction may be expected to accelerate the release of lead from the glaze and to serve, therefore, as a severe test that is unlikely to be matched under the actual conditions of usage of such ceramic ware. This test method is specific for lead and cadmium. 1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
ASTM C738-94(2020) is classified under the following ICS (International Classification for Standards) categories: 81.060.20 - Ceramic products. The ICS classification helps identify the subject area and facilitates finding related standards.
ASTM C738-94(2020) is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C738 − 94 (Reapproved 2020)
Standard Test Method for
Lead and Cadmium Extracted from Glazed Ceramic
Surfaces
This standard is issued under the fixed designation C738; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Apparatus
1.1 This test method covers the precise determination of 4.1 Atomic Absorption Spectrometer equipped with light
leadandcadmiumextractedbyaceticacidfromglazedceramic sources (hollow cathode or electrodeless discharge lamps)
surfaces. The procedure of extraction may be expected to specific for lead and cadmium, instrumental background
accelerate the release of lead from the glaze and to serve, correction, and a 4-in. (102 mm) single slot or Boling burner
therefore, as a severe test that is unlikely to be matched under head. Digital concentration readout may be used. Use air-
the actual conditions of usage of such ceramic ware. This test acetylene flame, instrumental background correction, and op-
method is specific for lead and cadmium. erating conditions recommended by instrument manufacturer.
Using these conditions, characteristic concentration (concen-
1.2 The values stated in SI units are to be regarded as
tration that gives 0.0044 absorbance) should be approximately
standard. The values given in parentheses after SI units are
(620 %) 0.2 and 0.45 ppm for Pb measured at 217.0 and
provided for information only and are not considered standard.
283.3 nm, respectively. Characteristic concentration should be
1.3 This standard does not purport to address all of the
approximately (620 %) 0.02 ppm for Cd.
safety concerns, if any, associated with its use. It is the
NOTE 1—1 ppm = 1 µg/mL.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
4.2 Lead Lamp, set at 283.3 or 217.0 nm.
mine the applicability of regulatory limitations prior to use.
4.3 Cadmium Lamp, set at 228.8 nm.
1.4 This international standard was developed in accor-
4.4 Glassware of chemically resistant borosilicate glass, to
dance with internationally recognized principles on standard-
make reagents and solutions. Clean by rinsing with dilute nitric
ization established in the Decision on Principles for the
acid(10 %byvolume)followedbycopiousquantitiesofwater.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
5. Reagents
Barriers to Trade (TBT) Committee.
5.1 Purity of Reagents—Reagent grade chemicals shall be
2. Summary of Test Method
used in all tests. Unless otherwise indicated, it is intended that
2.1 Lead and cadmium are extracted from the test article by
all reagents shall conform to the specifications of the Commit-
leaching with 4 % acetic acid for 24 h at 20 to 24 °C (68 to tee onAnalytical Reagents of theAmerican Chemical Society,
75 °F) and are measured by flame atomic absorption spectros-
where such specifications are available. Other grades may be
copy. used provided it is first ascertained that the reagent is of
sufficiently high purity to permit its use without lessening the
3. Interferences
accuracy of the determination.
3.1 There are no interferences when instrumental back-
5.2 Purity of Water—Unless otherwise indicated, references
ground correction and light sources specific for lead and
to water shall be understood to mean distilled water.
cadmium are used.
5.3 Acetic Acid (4 % by Volume)—Mix 1 volume of glacial
acetic acid with 24 volumes of water.
ThistestmethodisunderthejurisdictionofASTMCommitteeC21onCeramic
Whitewares and Related Productsand is the direct responsibility of Subcommittee
C21.03 on Methods for Whitewares and Environmental Concerns. This test method
was developed jointly by theAOAC andASTM, and adopted official final action by Reagent Chemicals, American Chemical Society Specifications, American
the Association of Official Analytical Chemists (method 973.32 AOAC Offıcial Chemical Society, Washington, DC. For suggestions on the testing of reagents not
Methods of Analysis (1990) 15th ed, AOAC International, Arlington, VA. listed by the American Chemical Society, see Analar Standards for Laboratory
Current edition approved Nov. 1, 2020. Published December 2020. Originally Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
published approved in 1972. Last previous edition approved in 2016 as and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
C738 – 94 (2016). DOI: 10.1520/C0738-94R20. MD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C738 − 94 (2020)
TABLE 1 Mean Value Required in Large Lot for Failure Rate
5.4 Detergent Wash—Use detergent designed for washing
1/10 000 with Coefficient of Variation 60 %
household dishes by hand. Mix with lukewarm tap water
Worstof6
according to product instructions.
Limit (ppm) Mean of 6
(Mean of 1)
5.5 Lead Nitrate Solution (1000-ppm Pb)—Dissolve
7 3.21 1.45
1.598 g of lead nitrate (Pb(NO ) ) in 4 % acetic acid and dilute 5 2.29 1.03
3 2
2.5 1.15 0.52
to 1 L with 4 % acetic acid. Commercially available standard
0.7 0.32 0.14
lead solutions may also be used.
0.5 0.23 0.10
0.25 0.11 0.05
5.6 Hydrochloric Acid (1 % by weight)—Mix 1 volume of
concentrated hydrochloric acid (HCl, sp gr 1.19) with 37
volumes of water.
exactly 0.1 volume of solution taken for concentration, cover
5.7 Cadmium Solution (1000-ppm Cd)—Dissolve 0.9273 g with watch glass, and swirl to complete dissolution. Calculate
ofanhydrouscadmiumsulfateinapproximately250mLof1 % leadconcentration(
...
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